I dunno what happened with that 2nd link ...
In it were useful specs for all types agroforestry including this one for Blackwood (Ac.melanoxylon).....
Blackwood for Farm Forestry
...which recommends 2.0 to 2.5m spacings
and this one for Ac.mearnsii (Blackwattle) ... which BTW are a very short lived species.
http://www.dpi.vic.gov.au/DPI/nrenin...0808_Nov07.pdf
and preliminaries for set-up
Site preparation for farm forestry